Consultant Sean Murphy offers these thoughts on business plans for bootstrappers based in turn on comments from Will Karmishlian at both Pelle Braendgaard's and this blog.

Murphy suggests:

Adapting von Moltke's observation that "No battle plan ever survives contact with the enemy" for a startup you might say that no startup's product or operating plan survives contact with the market, either in the form of customers or competition. But prior preparation enables quick response and will likely allow you to avoid unnecessary expense and some mistakes.

As this video showing VC Fred Wilson of Union Square Ventures receiving a singing proposal suggests, the traditional business plan format has become somewhat detached from reality with focus more on getting investors' attention than creating a realistic model.

Here are five tips for business planning in the bootstrapping process with the emphasis, as Sean suggests, on flexibility and constant change:
1. Use your blog as a business plan. (Sean suggests a Wiki) The idea in my case comes from a suggestion in a podcast with Feedburner's Dick Costolo about using the format as a way to continue iterating new ideas for a business roll out.
2. Stay fuzzy on projections and low on cost. Making earning projections for the next three years of a business that has not made even one dollar since day one is nearly impossible. Keeping costs low until revenue begins rolling in is good business sense.
3. DON'T position your product. As Guy Kawasaki points out in his post "The Top Ten Lies of Marketers", entrepreneurs don't position their product, customers do. Be sure to stay out of the way.
4. Focus on sales first. Plans that involve lots of investment and work before achieving any kind of reasonable cash flow are problematic. Instead use your plan to figure out how to start making money immediately then reinvest to grow your venture.
5. Target the proper audience-You! As comedy team Rex and Eddie suggest in this little skit, some business plans can't survive the simplest reality check.

Your plan should be able to tell you and your team in brief how to start operating your business almost immediately. If not, it's a waste of the cocktail napkin you scribbled it on.